The present invention relates to a thin film cutting appliance used for making cut-out masks for photoengraving.
According to a conventional method of cutting thin film, a colored translucent plastic thin film is overlaid on a photograph, which constitutes an original. The portion of the film, which has the same size as the outline of the photograph, is cut along the outline by a cutter so as to be used for subsequent design applications. According to another conventional method, a film coated with a light-blocking thin film is overlaid on a photograph, which constitutes an original, and the portion of the thin film, which has the same size as the outline of the photograph, is cut along the outline by a cutter. Each of the cutters is shaped like a stencil pen and held by the operator. It requires a substantial amount of skill to maintain each of the cutters at the prescribed angles, and since the inclination of the cutting edge of the cutter always changes, it makes it difficult to accurately cut the thin film.
For these reasons, an appliance has recently been developed and is disclosed in Japanese Utility Model Application (OPI) No. 197145/87 (the term "OPI" as used herein means an "unexamined published application"). The appliance has a frame shaped as a short cylinder or pipe and a level bottom end which is placed on a film coated with a light-blocking thin film. The level end is the bottom of the frame and the frame is then moved so that a portion of the thin film, which has a desired size, is cut out along the outline of a photograph by a cutter mounted inside the frame.
In the above-mentioned appliance, which is shown in FIG. 1, the cutter 4' is hung on a support arm 3' so as to extend down in the cylindrical frame 1' and is always urged downward by a plate spring 5' attached to the support arm. However, since the cylindrical frame 1' limits the field of vision, it is often difficult to properly align the cutting edge of the cutter 4' with respect to the photograph. Also, since the downward pressure applied to the cutter 4' by the plate spring 5' is constant, the cutting force of the cutter cannot be finely controlled like a stencil pen to efficiently cut the thin film.